Manumatic

Manumatic
Transmission types
Manual
Automatic
  • Manumatic
Semi-automatic
Continuously variable
Bicycle gearing
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Manumatic is a portmanteau of the words manual and automatic, that applies to a class of automotive transmissions.

Manumatic refers to an automatic transmission that allows convenient driver control of gear selection. This type of transmission was introduced in the 1990s. For most of automotive history, automatic transmissions already allowed some control of gear selection using the console or column shifter. Manumatics enhanced this feature by providing either steering wheel mounted paddle shifters or a modified shift lever for more convenient operation. Different car manufacturers have been using a variety of labels for their manumatic transmissions, such as 'Tiptronic', 'Geartronic', 'Touchshift', 'Sporttronic', and others.

A manumatic differs from a semi-automatic transmission in its method of power transfer from the engine to the transmission. A manumatic uses a torque converter, like a traditional automatic transmission, while a semi-automatic transmission uses a clutch (or multiple clutches), like a traditional manual transmission. Therefore, a semi-automatic transmission offers a more direct connection between the engine and wheels than a manumatic and is preferred in high performance driving applications. A manumatic is often preferred for street use because its fluid coupling makes it easier for the transmission to consistently perform smooth shifts. Some manumatic and semi-automatic transmissions allow the driver to have full control of gear selection, while many will intervene by shifting automatically at the low end and/or high end of the engine's operating range, depending on throttle position. Manumatics and most semi-automatic transmissions also provide the option of operating in the same manner as a conventional automatic transmission by allowing the transmission's computer to select gear changes.

Contents

Two pedal operation

The Automotive Products Manumatic and Newtondrive systems are also known as "two-pedal transmissions". They relieved the driver of the need for skill in operating clutch and engine speed in conjunction with the gear change.

Manumatic

A clutch servo powered by the vacuum at the induction manifold operated the automatic clutch - a conventional clutch incorporating centrifugal operation. A switch in the gear lever operated a solenoid valve so that when the gear lever was moved the clutch was disengaged. A control unit made throttle adjustments to keep the engine speed matched to the driven clutch plate and also varied the speed of clutch operation appropriate to road speed. [1]

Newtondrive

The Newtondrive system differed in making a provision for choke control and a cable linkage from clutch operating mechansim to the throttle.

The systems could be fitted to smaller cars such as the Ford Anglia

Tradenames

Tiptronic

Tiptronic is a registered trademark, owned by German sports car maker Porsche, who license it for use by other manufacturers, such as Land Rover and the Volkswagen Group (Audi, SEAT, Škoda and Volkswagen).

Many people (erroneously) use the term 'tiptronic' to refer generically to any type of torque converter automatic transmission that incorporates a manual upshift/downshift feature.

A tiptronic transmission can operate in the same manner as a conventional type of automatic transmission, but also offers the driver an additional method of manually overriding the automatic shift changes. By moving the shift lever into a second operating plane of the shift gate, equipped with two spring-loaded positions: "upshift" and "downshift", the driver takes over most of the gear shifting decisions, which would ordinarily be performed by the transmission's computer. For example, this allows delayed upshifts for increased acceleration, increased engine braking, gear holding in curves, downshifting before passing, or early upshifting for cruising. On some models, the upshift and downshift operations can also be controlled by push-buttons or "paddle shifters" installed on the steering wheel, with an optional display in the instrument panel indicating the current gear selection. Since adding tiptronic to a (semi-)automatic transmission involves an additional shift gate into the computer and update to the transmission software, it is inexpensive and lightweight to implement.

Although tiptronic transmissions allow the driver a certain measure of discrete control, the tiptronic design is implemented using a torque converter like other automatic transmissions. A true tiptronic transmission is not a computer controlled manual transmission (with a conventional clutch), or semi-automatic transmission. Most tiptronic implementations still make some shifts automatically, primarily to protect the engine and transmission. For example, as used by licensee Audi, the five-speed tiptronic will automatically make the upshift from 1 to 2 when moving off from a stop, even when in manual mode;[citation needed] the transmission then waits for the user's upshift command before proceeding from 2 to 3, 3 to 4 and 4 to 5, although the transmission will still upshift if the redline is approached. On deceleration, the transmission will make all downshifts automatically when close to the tick-over or idle speed, to prevent the engine from stalling at too-low an RPM, although the user can accelerate any downshift that would not exceed the redline.

Most luxury vehicles with a tiptronic transmission have two fully automatic modes: the primary mode, identified as "Drive", "Comfort" or similar; and another, usually called "Sport," which delays upshifts higher up the engine rev range (and will also downchange higher up the rev range) for a sportier driving and enhanced engine braking — at the expense of fuel, wear, comfort, and noise. Furthermore, because modern tiptronic-type transmissions use an electronic control unit (ECU), sometimes specifically referred to as the transmission control unit, the transmissions are able to adapt to the user's driving style through "fuzzy logic". Shift points are tailored to the habits of the driver, through an evolutionary process.

Tiptronic S

The Tiptronic S is an upgrade to the original Tiptronic, with the ability to adapt to driver's behaviour, and also allows driver to change gears without entering manual mode.[2] In manual mode, if there is no driver input for a period of eight seconds, the system reverts to automatic mode.[3] It was used as early as 2000 Porsche Boxster.[4]

In the Porsche Cayenne, the Tiptronic S was upgraded to six-speed.[5]

In the Porsche 911 (997) Turbo, the Tiptronic S model has faster acceleration over manual counterpart.[6]

See also

References


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